Is the measurement accuracy of fluorescence dissolved oxygen meter accurate
Due to the fact that the fluorescent material in front of the fluorescent cap only reacts with oxygen and does not consume oxygen during the process, it is not affected by other chemicals in the water and does not require stirring, resulting in more accurate measurements. The electrochemical measurement process consumes oxygen and is inherently imprecise, requiring agitation, and is easily affected by water quality and environmental factors, resulting in low efficiency. Moreover, electrochemistry can easily damage the bulbs on the head in harsh environments, resulting in a significant maintenance workload.
What are the benefits of optical dissolved oxygen meters compared to electrochemical dissolved oxygen meters?
Dissolved oxygen analyzer is an instrument used to measure the dissolved oxygen content in water. According to the measurement principle, there are two types: electrochemical and photochemical. Currently, most dissolved oxygen analyzers use electrochemical sensors. Although the accuracy and usability of electrochemical sensors are widely recognized, their drawbacks become apparent when used in wastewater treatment, and electrochemical sensors have obvious problems and limitations. Including complex and frequent daily maintenance, which often requires calibration; Moreover, the breathable film of the electrode is prone to aging; And it requires the redox reaction of the electrode itself to determine the concentration of oxygen, which requires the consumption of dissolved oxygen in the tested sample during the measurement process; And it also limits the measurement flow rate. In order to achieve equilibrium of diffusion controlled electrochemical reactions within the electrochemical cell, a minimum flow rate of 200mL/min needs to be maintained on the membrane surface. Below this flow rate, the measurement results are greatly affected by the water flow. In addition, excessive flow rate can also affect the thickness of the membrane and cathode electrolyte layer, thereby affecting the measurement results.
If the fluorescence dissolved oxygen analyzer is really good, why are there so many government projects that specify the use of electrochemistry?
Due to the fact that our country's national standard is electrochemical, fluorescence dissolved oxygen meters do not have a national standard, so some government projects are designed according to the national standard.
Why is the fluorescence dissolved oxygen analyzer so good and there is no national standard yet?
Because many large instrument manufacturers in China are still using old electrochemical technology from decades ago, they have not promoted fluorescence dissolved oxygen meters to become national standards.
